Extracted stay points:
laltitude	longitude	arriving time	leaving time
31.11065056950677 121.04980292675641 2009-06-28,04:43:02 2009-06-28,06:12:02
31.115610470899487 121.04836845149886 2009-06-28,07:13:52 2009-06-28,09:07:32
31.29601650943397 121.54464516037743 2009-06-28,12:18:12 2009-06-28,13:09:07
